Delivery-pump for liquids



oct. 1s, 1932.

DELIVERY PUMP Fon uourns. Filed ot. 24. 1930 `tormey R. Av1-@DOR 1,883,459

- Patented oet. 18,1932

UNITED STATES PATENT OFFICE RIFAT AVIGDOR, OF BERLIN-CHARLOTTENBURG, GERMANY DELIVERY-PUMP non LIQUIns .Application led October 24, 1930, Serial No. 490,993, and in Germany May 26, 1930.

This invention relateslto a diaphragm type pumpfor the delivery of fluids. The particular application described is that of moving fuel from a main tank to a carburetor. However, I do not propose to limit the application of the pump to this particular function as there are many other uses to which itmay be put. v

Most diaphragm pumps exhibit' fatigue phenomena after a short period of use, be-

gin to leak, and finally fail altogether. The membrane is flexed by'a series ofsharp impaets delivered by the driving system, and under these successive shocks the membrane finally weakens. The pump as here disclosed employs a resilient drive which eliminates all shock in the system.

Another disadvantage has been that considerable time elapses while` the liquid column 2o is moving from the main tank to the point of delivery. In the case of a vehicle so equipped there is a prolonged drain on the starting battery which continues until fuel has reached the motor. The present invention 2 5 provides a secondary fuel reservoir and filter adjacent the pump structure to insure immediate supply of fuelto the motor during the period when fuel is being drawn from the main tank. An intake pipe is introduced into the secondary reservoir and is provided with one or a plurality of suction openings at'its lower end. The fuel therefore immediately drawn from the secondary reservoir without the delay of having to transfer the fuel from the main tank. For the purpose of insuring easier movement of the liquid from the main tank, the upper end of the intake lpipe is provided with one or a plurality of small openings. By means pfthese openings the 40 air will be drawn from the secondary reservoir, rendering the formation of an air chamber unnecessary.

Owing to the constructional arrangement of the pump drive in accordance with the present invention, the pump may be utilized forwork other than the delivery of liquids.

The pump may be used for delivering comressed air from the air-chamber or for creat.

lng a vacuum and for this reason it may be be employed actuating instruments and-- ships and the like as the like in aeroplanes,

It is possible well as in stationary plants.-

.to connect with the delivery pump pneumatic liquid, oil and gasoline pressure meters, remote revolution indicators, trochometers and the like. The' current ofair which may beV produced by the delivery pump can be conducted past heating points or warm .air may be directly employed for heating the nozzles of dynamic pressure gauges or similar in-` 00 struments used onaeroplanes and air-ships. This warm air will prevent the blocking of the nozzles, and ofthe measuring instruments,'by ice as well as the possibility of the delivery device and of the pump itself becoming blocked with ice.

The arrangement of thedelivery pump forA the purpose of delivering compressed air or for the purpose of creating a vacuum consists as follows: 70

In the lair chamber, which is separated from the liquid chamber by the-diaphragm, each cycle of the pump produces a compress-- ing and rarefyingvefi'ect alternately. By the provision of suitable inlet and outlet valves an exact regulation of the delivery of compressed air or of the vacuum is insured.

. The invention is described more in detail in the portion of the specification which fol-' lows, with reference to the yaccompanying 8o drawing in which the pump-is shown in cross section: y

In ,the drawing is shown' a casing 1 which ycontains a flexible diaphragm 2. This diaphragm is clamped by means of a screw joint between two rigid disks and is attached to a bolt'A 3 having a shoulder 4 and a rounded head or guide portion 4. A tubular shaft 5 encloses the shoulder and head, the other end of the shaft contacting a shoulder 6 formed -00 on a projection of the cam plate 6. A socketmember 7 of the casing surrounds. the tubular shaft, forming an air-tight joint. The cam platev 6 is driven by an eccentric cani-23 which is attached to the/motor, shaft. A strg'mg 95 spiral spring 8 holds the cam plate in engage ment with the eccentric cam, while .a weakery spring 9, when the cam plate 6 is raisedf and the' spring 8 compressed, drives the diaphragm in the opposite cycle ofthe stroke.

the upper end with ventilation openings of a smaller diameter. The intake pipe is enclosed by' a lter-16. The liquid path is from the socket connection 19 through inlet opening 18 and the intake pipe, downwardly through tube 10 and out through discharge port 20 which may lead to an intake manifold or other suitable device.

It will be seen that .the diaphragm is actuated through the medium of two differential springs adjusted in relation to each other.

The weaker spring `actuates the diaphragm or the compression cyclewhile the stronger effects the withdrawal of the diaphragm or the suction cycle. If an excess pressure is built-up in the pump chamber which exceeds that for which the weaker spring has been adjusted, the stroke o this weaker spring will be reduced according to the existing eX- cess, causing a proportionally lesser bending of the diaphragm for the pressure cycle. If the pump outlet becomes completely blocked, the bending ofthe diaphragm will cease altogetherand thus the pump regulates itself automatically in accordance with fuel consumption.

In order to utilize the other side of the diaphragm, an inlet valve 21 and an outlet valve 22 has been provided in a space at the' lower side of the diaphragm chamber. This makes it possible vfor the pump to erform a dual function. In addition tot e pumping of liquids or .fuels another pumpingchamber is made available and vmay be used for pumping gases and the like from the air chamber of the secondary reservoir 17, or for ventilation, or to deliver compressed air or as to any kind of control device applied to the action of the pump. Many other applicatlons of thisdual purpose pump maybe readily defined. Owing to the fact that the quantity of air or gas conveyed through the chamber -upon the reverse side of the membrane is dependent upon the size and number of diaphragm strokes,'the quantity of air conveyed would always be in a precise ratio to the quantity of liquid lconveyed and therefore it may be used in the measuring ofthe volume of liquid delivered.

What I claim is:

1.' In a fuel pump including a flexible diaphragm, a bolt secured to the diaphragm having a shoulder and a rounded head comprising a guide, a cam plate having'a projecting portion carrying a shoulder, a driving eccentric cam in contact with said c am plate, a tubular shaft engaging said shoulders and establishing a loose driving connection therewith, and resilient means cooperating with said cam plate and said diaphragm for effecting a resilient drive.

. 2. In a fuel pump including a flexiblev diaphragm, a bolt secured to the diaphragm having a shoulder" and a rounded head comprising a guide, `a cam plate having a projecting portioncarrying a shoulder, a driving eccentric`cam in contact with said cam plate, a tubular shaft having a constricted portion engaging said shoulders and establishing a loose driving silient means cooperating with said cam plate and said diaphragm for effecting a resilient drive.

3. In a diaphragm ump having two chambers separated by said) diaphragm, outlet and inlet valves foreach chamber, a bolt secured to said diaphragm, having a shoulder and a rounded head comprising a guide, a cam plate having a projecting portion carrying a shoulder, a driving eccentric cam in contact with said cam plate, a tubular shaftengaging said shoulders and establishing a loose driving connection therewith, and resilient Vmeans cooperating with said cam plate and connection therewith, and re- 

